Referring to FIG. 14, a conventional crankshaft 101 has a shaft section 102, a crank arm 103, and a crankpin 104 for arranging a con rod between the adjacent crank arms 103.
In addition, a rolling bearing to rotatably support the shaft section 102 of the above crankshaft 101 is disclosed in Japanese Patent Publication No. 7-506889, for example. The rolling bearing disclosed in the above patent document includes an outer ring, a plurality of rolling components arranged along an inner diameter surface of the outer ring, and a retainer to retain the plurality of rolling components.
The above rolling bearing is assembled by incorporating a roller and retainer assembly, the outer ring, and a housing into the shaft section 102 in this order. In addition, in order to enable them to be radially incorporated in the shaft section 102 sandwiched between the crank arms 103, the outer ring is a split type outer ring including a first arcuate section having a center angle larger than 180° and a second arcuate section having a center angle smaller than 180°.
Here, since the first section has a cut site dimension smaller than a maximum outer diameter of the roller and retainer assembly, it has to be elastically deformed in a direction to enlarge the cut site when incorporated. In addition, an elastic deformation volume of the first section increases as the center angle of the first section increases. Meanwhile, elastic deformability reduces with increasing thickness of the first section. Therefore, the outer ring cannot be easily incorporated depending on a dimensional relationship in the bearing.